Unless you are trying to 'restore' the carbine to the original configuration of June 1943 (very expensive and difficult to do right) the USGI adjustable sight, either the milled or stamped version, is by far the better sight. That's why Uncle Sam developed them. The adjustable sights are much easier to get your shot where you want it to be on your target and also give you better selection of elevation (range) adjustment than the older fixed leaf type flip sight. I personnally think the earlier milled adjustable sight is a better made sight than the later stamped version but they both work very well and they are both available at a very reasonable price. JMHO